You can still be banned from the U.S. if you admit to pot use or if you say you work in (legal) cannabis. You read that right. Just admitting to having used marijuana in the past could get you a lifetime ban from the U.S.

Even if the place you're visiting -- Washington State -- has made it legal and the place you live -- Canada -- has made it legal. And just to be sure, they'll put the sniffer dogs on you.